190 research outputs found

    Fabrication and catalytic activity of thermally stable gold nanoparticles on ultrastable Y (USY) zeolites

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    Au was deposited on ultrastable Y (USY) zeolites using an ion-exchange method. Up to 5.5 wt% Au was introduced into the NH4-form of USY zeolites. In contrast, deposition of Au hardly took place on the H- and Na-forms of Y-type zeolites, NH4-forms of mordenite, and ZSM-5. Treatment of the Au-loaded USY zeolite in a H2 atmosphere, afforded Au0 nanoparticles. These particles were thermally stable even at 973 K, where their mean particle diameter was 3.7 nm. In contrast, highly aggregated Au particles were observed after thermal treatment at temperatures lower than 523 K, followed by storage in air for a month. The resulting particle sizes were in good correlation with the IR band intensity of the adsorbed CO and the catalytic activity of Au in the aerobic oxidation of benzyl alcohol. The Au nanoparticles showed highest activity when the Au/USY zeolite was thermally treated at 673–973 K. A negligible deactivation was observed after repeating the reaction at least 12 times. In the case of Au/TiO2 catalyst prepared by the deposition-precipitation method, the highest activity was observed at 573 K, which was lower than the temperature used for the Au/USY zeolites. This study demonstrated the potential use of the NH4-form of USY zeolites for supporting Au

    Adsorption of Urinary Proteins on the Conventionally Used Urine Collection Tubes: Possible Effects on Urinary Proteome Analysis and Prevention of the Adsorption by Polymer Coating

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    One possible factor determining recovery of trace amount of protein biomarker candidates during proteome analyses could be adsorption on urine tubes. This issue, however, has not been well addressed so far. Recently, a new technical device of surface coating by poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)) (poly(MPC-co-BMA)) has been developed mainly to prevent the adsorption of plasma proteins. We assessed whether conventionally used urine tubes adsorb trace amount of urinary proteins and, if any, whether the surface coating by poly(MPC-co-BMA) can minimize the adsorption. Proteinuric urine samples were kept in poly(MPC-co-BMA)-coated and noncoated urine tubes for 15 min and possibly adsorbed proteins and/or peptides onto urine tubes were analyzed by SDS-PAGE, 2-DE, and the MALDI-TOF MS. It was found that a number of proteins and/or peptides adsorb on the conventionally used urine tubes and that surface coating by poly(MPC-co-BMA) can minimize the adsorption without any significant effects on routine urinalysis test results. Although it remains to be clarified to what extent the protein adsorption can modify the results of urinary proteome analyses, one has to consider this possible adsorption of urinary proteins when searching for trace amounts of protein biomarkers in urine

    Molecular Network Associated with MITF in Skin Melanoma Development and Progression

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    Various environmental and genetic factors affect the development and progression of skin cancers including melanoma. Melanoma development is initially triggered by environmental factors including ultraviolet (UV) light, and then genetic/epigenetic alterations occur in skin melanocytes. These first triggers alter the conditions of numerous genes and proteins, and they induce and/or reduce gene expression and activate and/or repress protein stability and activity, resulting in melanoma progression. Microphthalmia-associated transcription factor (MITF) is a master regulator gene of melanocyte development and differentiation and is also associated with melanoma development and progression. To find better approaches to molecular-based therapies for patients, understanding MITF function in skin melanoma development and progression is important. Here, we review the molecular networks associated with MITF in skin melanoma development and progression

    Glucotoxicity Induces Insulin Promoter DNA Methylation in Beta Cells

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    Recent studies have implicated epigenetics in the pathophysiology of diabetes. Furthermore, DNA methylation, which irreversibly deactivates gene transcription, of the insulin promoter, particularly the cAMP response element, is increased in diabetes patients. However, the underlying mechanism remains unclear. We aimed to investigate insulin promoter DNA methylation in an over-nutrition state. INS-1 cells, the rat pancreatic beta cell line, were cultured under normal-culture-glucose (11.2 mmol/l) or experimental-high-glucose (22.4 mmol/l) conditions for 14 days, with or without 0.4 mmol/l palmitate. DNA methylation of the rat insulin 1 gene (Ins1) promoter was investigated using bisulfite sequencing and pyrosequencing analysis. Experimental-high-glucose conditions significantly suppressed insulin mRNA and increased DNA methylation at all five CpG sites within the Ins1 promoter, including the cAMP response element, in a time-dependent and glucose concentration-dependent manner. DNA methylation under experimental-high-glucose conditions was unique to the Ins1 promoter; however, palmitate did not affect DNA methylation. Artificial methylation of Ins1 promoter significantly suppressed promoter-driven luciferase activity, and a DNA methylation inhibitor significantly improved insulin mRNA suppression by experimental-high-glucose conditions. Experimental-high-glucose conditions significantly increased DNA methyltransferase activity and decreased ten-eleven-translocation methylcytosine dioxygenase activity. Oxidative stress and endoplasmic reticulum stress did not affect DNA methylation of the Ins1 promoter. High glucose but not palmitate increased ectopic triacylglycerol accumulation parallel to DNA methylation. Metformin upregulated insulin gene expression and suppressed DNA methylation and ectopic triacylglycerol accumulation. Finally, DNA methylation of the Ins1 promoter increased in isolated islets from Zucker diabetic fatty rats. This study helps to clarify the effect of an over-nutrition state on DNA methylation of the Ins1 promoter in pancreatic beta cells. It provides new insights into the irreversible pathophysiology of diabetes

    Epitaxial growth of topological insulator Bi2Se3 film on Si(111) with atomically sharp interface

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    Atomically sharp epitaxial growth of Bi2Se3 films is achieved on Si (111) substrate with MBE (Molecular Beam Epitaxy). Two-step growth process is found to be a key to achieve interfacial-layer-free epitaxial Bi2Se3 films on Si substrates. With a single-step high temperature growth, second phase clusters are formed at an early stage. On the other hand, with low temperature growth, the film tends to be disordered even in the absence of a second phase. With a low temperature initial growth followed by a high temperature growth, second-phase-free atomically sharp interface is obtained between Bi2Se3 and Si substrate, as verified by RHEED (Reflection High Energy Electron Diffraction), TEM (Transmission Electron Microscopy) and XRD (X-Ray Diffraction). The lattice constant of Bi2Se3 is observed to relax to its bulk value during the first quintuple layer according to RHEED analysis, implying the absence of strain from the substrate. TEM shows a fully epitaxial structure of Bi2Se3 film down to the first quintuple layer without any second phase or an amorphous layer.Comment: 20 pages, 7 figure

    Análisis de las comorbilidades en pacientes con colitis ulcerosa: una herramienta para prevenir las exacerbaciones en casos de colitis ulcerosa

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    There have been previous studies, especially in Western countries and even in some areas in Asia, about extra-intestinal manifestations (EIMs) and its link with the outcome of inflammatory bowel disease (IBD), which includes Crohn’s disease (CD), and ulcerative colitis (UC). This link is crucial when discussing a patient’s prognosis and important when dealing with UC management. The aim of this study was to clarify the most common comorbidities associated with UC, emphasizing immunologic comorbidities in Japan. This study was a retrospective analysis performed at Nagoya University Hospital. The data collection started in March, 2019, and continued for two years. We retrieved the medical records of 105 patients with UC diagnosis, from which the data of 176 EIMs were extracted and analyzed. Results showed that EIMs with UC in the active phase accounted for 43.7% of total EIMs. Twenty-six patients with immune-mediated inflammatory disease frequently had an active phase (odds ratio [OR] 3.84, 99% CI, 1.44–10.27). Comorbidities showing an active manifestation of symptoms and UC in the active phase were significantly correlated in patients with immunological comorbidities, such as peripheral arthritis (r = 0.97, p < 0.01) and rheumatoid arthritis (RA) (r = 0.99, p < 0.01), as well as in patients with primary sclerosis cholangitis (PSC) (r = 0.98, p < 0.01). In conclusion, this analysis suggests the importance of having full comprehension of how immunological comorbidities affect the natural development of UC, which is of vital importance to prevent further UC complications and properly adjust the management of the disease.Se trata de un análisis retrospectivo que estudia múltiples comorbilidades de índole inmunológico que se da en pacientes con colitis ulcerosa. Este estudio se llevó a cabo en el hospital universitario de la Universidad de Nagoya. Se recolectó datos de 105 pacientes con colitis ulcerosa, de los cuales 176 comorbilidades extraintestinales fueron analizadas. Se encontró que comorbilidades con manifestación activa de síntomas y con colitis ulcerosa en fase activa fueron significativamente correlacionadas en pacientes con comorbilidades inmunológicas, tales como artritis periféricas (r=O.97, P<O.OI ), artritis reumatoide (r=O.99, P<O.OI ), así como pacientes con colangitis esclerosa primaria (r=O.98, P<O.OI ). En conclusión, este análisis sugiere la importancia de tener plena comprensión de cómo las comorbilidades inmunológicas afectan el desarrollo natural de la colitis ulcerosa, lo cual es de vital importancia para prevenir mayores complicaciones de la colitis ulcerosa y ajustar adecuadamente el manejo de la enfermedad.Japón. Ministerio de Educación, Cultura, Deportes, Ciencia y Tecnología (Monbukagakusho)Artículo de investigació

    The Satb1 Protein Directs Hematopoietic Stem Cell Differentiation toward Lymphoid Lineages

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    SummaryHow hematopoietic stem cells (HSCs) produce particular lineages is insufficiently understood. We searched for key factors that direct HSC to lymphopoiesis. Comparing gene expression profiles for HSCs and early lymphoid progenitors revealed that Satb1, a global chromatin regulator, was markedly induced with lymphoid lineage specification. HSCs from Satb1-deficient mice were defective in lymphopoietic activity in culture and failed to reconstitute T lymphopoiesis in wild-type recipients. Furthermore, Satb1 transduction of HSCs and embryonic stem cells robustly promoted their differentiation toward lymphocytes. Whereas genes that encode Ikaros, E2A, and Notch1 were unaffected, many genes involved in lineage decisions were regulated by Satb1. Satb1 expression was reduced in aged HSCs with compromised lymphopoietic potential, but forced Satb1 expression partly restored that potential. Thus, Satb1 governs the initiating process central to the replenishing of lymphoid lineages. Such activity in lymphoid cell generation may be of clinical importance and useful to overcome immunosenescence

    Solitary Peutz-Jeghers type hamartomatous polyps in the duodenum are not always associated with a low risk of cancer: two case reports

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    INTRODUCTION: A hamartomatous polyp without associated mucocutaneous pigmentation or a family history of Peutz-Jeghers Syndrome is diagnosed as a solitary Peutz-Jeghers type hamartomatous polyp. As compared with Peutz-Jeghers Syndrome, Peutz-Jeghers type hamartomatous polyps are diagnosed with a lower risk of cancer and are regarded as a different disorder. CASE PRESENTATION: In case one, we describe an 84-year-old Japanese man with a 14 mm duodenal polyp. Endoscopic mucosal resection was performed and histological examination showed findings suggestive of a hamartomatous polyp with a focus of well-differentiated adenocarcinoma. In case two, we describe a 76-year-old Japanese man who had been treated for prostate, rectal and lung cancer. Upper gastrointestinal endoscopy revealed a duodenal polyp measuring 15 mm in diameter. Endoscopic mucosal resection was performed, and histological examination showed findings suggestive of a hamartomatous polyp. Liver and thyroid cancers were found after the endoscopic treatment. CONCLUSION: Although duodenal solitary hamartomatous polyps are associated with a lower risk of cancer, four patients, including our cases, have been diagnosed with cancerous polyps. Patients with duodenal solitary hamartomatous polyps should be treated by endoscopic or surgical resection and need whole-body screening
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